Reconstructed primary fragments and symmetry energy, temperature and density of the fragmenting source in $^{64}$Zn + $^{112}$Sn at 40 MeV/nucleon

TL;DR

This study reconstructs primary hot isotope yields in a nuclear reaction to determine symmetry energy, temperature, and density of the fragmenting source using experimental data and AMD simulations, providing insights into nuclear matter properties.

Contribution

It introduces a self-consistent method combining experimental reconstruction and AMD simulations to extract symmetry energy, temperature, and density in nuclear multifragmentation.

Findings

Density of the fragmenting system is approximately 0.65 times nuclear saturation density.

Symmetry energy at the fragmenting source is about 23.1 MeV.

Temperature of the fragmenting source is around 5.0 MeV.

Abstract

Symmetry energy, temperature and density at the time of the intermediate mass fragment formation are determined in a self-consistent manner, using the experimentally reconstructed primary hot isotope yields and anti-symmetrized molecular dynamics (AMD) simulations. The yields of primary hot fragments are experimentally reconstructed for multifragmentation events in the reaction system $^{64}$Zn + $^{112}$Sn at 40 MeV/nucleon. Using the reconstructed hot isotope yields and an improved method, based on the modified Fisher model, symmetry energy values relative to the apparent temperature, $a_{sym}/T$, are extracted. The extracted values are compared with those of the AMD simulations, extracted in the same way as that for the experiment, with the Gogny interaction with three different density-dependent symmetry energy terms. $a_{sym}/T$ values change according to the density-dependent symmetry energy terms used. Using this relation, the density of the fragmenting system is extracted first. Then symmetry energy and apparent temperature are determined in a self consistent manner in the AMD model simulations. Comparing the calculated $a_{sym}/T$ values and those of the experimental values from the reconstructed yields, $\rho /\rho_{0} = 0.65 \pm 0.02 $, $a_{sym} = 23.1 \pm 0.6$ MeV and $T= 5.0 \pm 0.4$ MeV are evaluated for the fragmenting system experimentally observed in the reaction studied.